Combination boat trim tab and heat exchanger

ABSTRACT

A combination boat trim tab and heat exchanger for an engine driven boat in which the trim tab body is hollow and has an inlet and outlet connected to the hollow interior and is adapted to be connected to the boat engine cooling system with elongate fins secured to the bottom of the outside of the body and axially aligned with the longitudinal axis of the boat. The hollow interior of the body including a serpentine passageway between the inlet and outlet thereby increasing the heat exchange area in contact with the engine cooling liquid. Elongate cooling fins secured to the interior of the bottom of the body for increasing the cooling surface.

United States Patent Childress 51 Mar. 21, 1972 COMBINATION BOAT TRIM TAB AND HEAT EXCHANGER 3,240,179 3/1966 Van Ranst ..l65/44 X Primary Examiner-Frederick L. Matteson Assistant Examiner-W. C. Anderson AttarneyJames F. Weiler, Jefferson D. Giller, William A. Stout, Paul L. De Verter, ll, Dudley R. Dobie, Jr. and Henry W. Hope [57] ABSTRACT A combination boat trim tab and heat exchanger for an engine driven boat in which the trim tab body is hollow and has an inlet and outlet connected to the hollow interior and is adapted to be connected to the boat engine cooling system with elongate fins secured to the bottom of the outside of the body and axially aligned with the longitudinal axis of the boat. The hollow interior of the body' including a serpentine passageway between the inlet and outlet thereby increasing the heat exchange area in contact with the engine cooling [72] Inventor: Ezra E. Childress, Houston, Tex.

[73] Assignee: Stewart & Stevenson Services, Inc.,

Houston, Tex.

[22] Filed: July 16,1970

[21] Appl.No.: 55,427

[52] U.S.Cl ..l65/44,1l5/0.5,ll4/66.5P [5|] lnt.Cl. ..F28t7/00 [58] FieldoiSearch ..l65/41,44;ll5/0.5; 114/665? [56] References Cited UNITED STATES PATENTS 2,386,803 10/1945 3,200,782 8/1965 3,327,776 6/1967 2,976,834 3/1961 Waldronetal. ..ll5/0.5

5 Claims, 4 Drawing Figures COMBINATION BOAT TRIM TAB AND I-IEAT EXCHANGER BACKGROUND OF THE INVENTION It is often desirable to provide sufficient cooling or to increase the cooling capacity of an engine operating a boat. Since the water in which the boat is operated provides a tremendous reservoir of cooling liquid, it would be useful to use the water for cooling the boat engine. However, since the waters in which boats operate are frequently corrosive or damaging, for example, salt water, to the internal parts of the engine, it is not generally desirable to use the boating waters as a direct cooling source. But, of course, any indirect cooling structure should be efficient, and should not interfere with the operational performance of the boat.

Since boat trim tabs do not interfere with, but on the contrary assist, the operational performance of a boat, the present invention is directed to providing a combination boat trim tab and heat exchanger for an engine driven boat which will increase the cooling capacity of the engine without subjecting the internal working parts of the engine to the water in which the boat operates and yet will not interfere with the operational performance of the boat. The combination boat trim tab and heat exchanger of the present invention is also directed to provide sufficient cooling for the engine both when the boat is moving and while it rests.

SUMMARY The present invention is directed to a combination boat trim tab and heat exchanger for an engine driven boat in which the trim tab body is adapted to be secured to a boat and has a hollow interior with an inlet and outlet connected to the hollow interior of the body and spaced from each other and adapted to be connected to the boat engine cooling system.

Another feature of the present invention is the provision of elongate cooling fins secured to the bottom of the outside of the boat to provide an increased heat exchange area and which are axially aligned with the longitudinal axis of the boat so as not to decrease the operational performance of the trim tab and boat.

Still another feature of the present invention is the provision of a hollow trim tab body having a cooling inlet and outlet wherein the body includes an internal serpentine passageway between the inlet and the outlet thereby increasing the heat exchange area between the cooling liquid and the body.

A still further feature of the present invention is the provision of internal elongate cooling fins secured to the interior of the bottom of the body wherein the interior fins are preferably aligned with the majority of a serpentine passageway.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary elevational view of an engine driven boat provided with a pair of combination trim tabs and heat exchangers,

FIG. 2 is an enlarged fragmentary elevational view of the improved trim tab of the present invention,

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2, and

FIG. 4 is an elevational view of the trim tab of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, and particularly FIGS. 1 and 2, the boat of the present invention generally includes an engine 12 driving a propeller 14 as is conventional.

One or more trim tabs generally indicated by the reference numeral 16 may be provided connected to the boat 10. The trim tab 16 may either be fixedly secured to the boat or as shown in FIG. 2 pivotally secured by one or more hinges l8 and movably positioned by a suitable means such as a hydraulic piston and cylinder assembly 20 connected at one end 22 to the boat and at a second end 24 to the trim tab 16.

The trim tab 16 of the present invention includes a hollow interior 25, as best seen in FIGS. 3 and 4, and includes an inlet 26 and an outlet 28 in communication with the hollow interior 25. The inlet 26 and outlet 28 are spaced from each other and adjacent opposite sides of the trim tab 16 to insure that the cooling liquid flowing from the inlet 26 to the outlet 28 comes' in contact with a greater area of the body of the trim tab 16 for increased heat exchange. As best seen in FIG. 1, the inlets 26 and outlets 28 from the trim tabs 16 are suitably connected by lines 30 and 32, respectively, to the cooling system of the boat engine 12. The trim tab 16 is of a suitable material such as metal having a high rate of thermal conductivity for heat exchange between the engine cooling fluid flowing through the interior of the trim tabs 16 and the water contacting the outside of the trim tabs 16.

Of course, while the boat 10 is at rest or idling, the boat 10 will sit lower in the water and both the bottom surface 34 and the top surface 36 of the trim tab 16 will be underwater. Since at idling or low speeds, the heat dissipation requirements of the engine cooling system are lower, the submersion of the trim tab 16 underwater, even though at rest, will provide a sufficient cooling area to satisfy the engine cooling requirements.

However, as the boat 10 gets underway, the action of the trim tabs 16 will cause the boat 10 to rise up on top of the water and only the lower surface 34 of the trim tab 16 will be in contact with the water. Therefore, in order to increase the heat exchange capacity of the trim tab 16 relative to the water, a plurality of the elongate cooling fins 38 are provided secured to preferably the entire bottom 34 of the outside of the trim tab body. In addition, the elongate cooling fins 38 are aligned with the longitudinal axis of the boat 10 to provide a structure which will not interfere with the operational performance of the trim tab 16 nor the boat 10.

In order to further increase the cooling capacity of the trim tab 16, and as best seen in FIGS. 3 and 4, partitions 40, 42 and 44 are provided in the hollow interior 25 of the trim tab 16 whereby the hollow interior 25 forms a serpentine passageway between the inlet 26 and 28 since the barriers 40, 42 and 44 alternately extend from opposite sides, but do not extend entirely across the hollow interior 25 of the trim tab 16. Therefore, the engine cooling fluid flowing from the inlet 26 to the outlet 28 will contact a greater surface area and thus increase the heat exchange cooling area between the cooling liquid and the body of the trim tab 16.

Additional cooling may be provided if necessary by providing elongate cooling fins 50 secured to the interior of the bottom 34 of the trim tab 16. Preferably, the interior cooling fins 50 are generally aligned with the major passageways of the serpentine path of flow of the cooling liquid from the inlet 26 to the outlet 28.

In use, and as previously indicated, with the boat 10 at rest and idling the entire trim tab 16 will be submerged in the water and even though not in moving contact with the water will provide sufficient cooling to cool the engine under light loads. And when the boat 10 is underway and the engine is under a heavier load, while only the bottom 34 of the trim tab 16 will be in contact with the water, sufficient heat exchange will be provided by the water in which the boat travels moving across the exterior cooling fins 30 while the engine cooling fluid flows through the interior 25 of the trim tab 16. In addition the serpentine path of flow and the interior cooling fins 50 increase the heat exchange.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein.

What is claimed is:

l. A combination boat trim tab and heat exchanger for an engine driven boat comprising,

a generally horizontally positioned trim tab body having means adapting said body to be secured to a boat and having a hollow interior,

an inlet and an outlet connected to the interior of the body and spaced from each other and adjacent opposite sides elongate cooling fins secured to the interior of the bottom of I the body.

4. A combination boat trim tab and heat exchanger for an engine driven boat comprising,

a flat bottom generally horizontally positioned trim tab body having means adapting said body to be secured to a boat,

said body being hollow and including an inlet and an outlet connected to the interior of the body and spaced from each other and adjacent opposite sides and adapted to be connected to the boat engine cooling system, said hollow interior of the body including a serpentine passageway between the inlet and outlet thereby increasing the heat exchange cooling area between the cooling liquid and the body, elongate fins secured to the bottom of the outside of the body and axially aligned with the longitudinal axis of the boat, and elongate cooling fins secured to the interior of the bottom of the body. 5. The apparatus of claim 4 wherein the interior cooling fins are generally aligned with the serpentine passageway. 

1. A combination boat trim tab and heat exchanger for an engine driven boat comprising, a generally horizontally positioned trim tab body having means adapting said body to be secured to a boat and having a hollow interior, an inlet and an outlet connected to the interior of the body and spaced from each other and adjacent opposite sides and adapted to be connected to the boat engine cooling system, and elongate cooling fins secured to the bottom of the outside of the body and axially aligned with the longitudinal axis of the boat.
 2. The apparatus of claim 1 including, said hollow interior of the body having a serpentine passageway between the inlet and outlet thereby increasing the heat exchange area of the cooling liquid flowing therein.
 3. The apparatus of claim 1 including, elongate cooling fins secured to the interior of the bottom of the body.
 4. A combination boat trim tab and heat exchanger for an engine driven boat comprising, a flat bottom generally horizontally positioned trim tab body having means adapting said body to be secured to a boat, said body being hollow and including an inlet and an outlet connected to the interior of the body and spaced from each other and adjacent opposite sides and adapted to be connected to the boat engine cooling system, said hollow interior of the body including a serpentine passageway between the inlet and outlet thereby increasing the heat exchange cooling area between the cooling liquid and the body, elongate fins secured to the bottom of the outside of the body and axially aligned with the longitudinal axis of the boat, and elongate cooling fins secured to the interior of the bottom of the body.
 5. The apparatus of claim 4 wherein the interior cooling fins are generally aligned with the serpentine passageway. 